DENVER—John Van Dyk says he needs to hire 80 construction framers this year to keep up with Colorado's recovering home-building market, doubling his company's size. So far, he has hired only 20.

"We're really concerned about this summer," said Mr. Van Dyk, whose Van Dyk Construction Inc. employs carpenters who assemble and erect housing frames. "For the first time in my 35-year career, I have to think of whether I...